Understood. Most players will leave if told they won't play. My impression is that Lieb is a very bright kid who does not expect a professional career. An Illinois degree might have real value for him.That is correct.
But for guys that want to get minutes during games, a coach saying "I don't know that I can get you minutes next season" can motivate a player to move on to a new team. I am NOT saying that this is the case for Lieb, as he may indeed wish to stay anyway. I have no idea, nor is it my business.
What I am saying is that, as an example, guys with dreams of professional play, particularly the NBA (however realistic or not that may appear to us), hearing in April that playing time may not be available next season may decide that their best move is to transfer.